[2] When the American Automobile Association (AAA) withdrew from auto racing after the 1955 season, citing the Le Mans disaster and the death of Bill Vukovich at Indianapolis as contributing factors,[3] both the SCCA and NASCAR were mentioned as its potential successor.

For a while there was a separate series of specifications for championship cars designed to be run on dirt, rather than paved, tracks.

Six other drivers, Pancho Carter (1972–78), Dave Darland (1997–2001), Jerry Coons Jr. (2006–08), Tracy Hines (2000, 2002, 2015), Chris Windom (2016, 2017, 2020), and Logan Seavey (2023-2024) have claimed each of the three championships at least once in their careers.

[citation needed] USAC had awarded a national championship until A. J. Foyt won his seventh title in 1979.

[6] Bryan Clauson of Noblesville, Indiana claimed the inaugural championship, topping runner-up Levi Jones by 14 points.

[7][8] Killed were:[9] The incident closely followed the death of Indianapolis Motor Speedway owner Tony Hulman.

[8] The plane crash came at a time when Indy car owners and drivers were demanding changes from USAC.

The seed of dissent had been growing for several years before the accident,[11] and claims the crash was an immediate cause for the 1979 CART/USAC "split" are considered for the most part unfounded.

USAC tried unsuccessfully to ban all CART owners from the 1979 Indianapolis 500, finally losing in court before the race began.

Indianapolis Motor Speedway president John Cooper was instrumental in forming a joint body of CART and USAC with the creation of the Championship Racing League in March 1980.

Since 2022, the United States Auto Club has sanctioned the USF Juniors, USF2000 Championship, and USF Pro 2000 Championship series, which serve as a ladder series to Indy NXT, along with the Radical Sportscars North American Championships, Skip Barber Racing School, as well as continued sanctioning of the GT World Challenge America and Porsche Sprint Challenge North America under the newly formed Road Racing Division under the direction of Randy Hembrey.

* As of the end of the 2022 season From 1956 to 1960, USAC's National Sprint Car Championship was divided into two regional divisions in the Midwest and the East.

The series also features combination races with the AMSOIL USAC Sprint Car National Championship.

It is sanctioned by USAC,[43] though Gordon and sponsorship marketing company The Elevation Group co-own the series.

The winner of the Indianapolis 500 would be the de facto Gold Crown champion, as it was the lone points-paying event.

* The inaugural season featured two subtitles: Pacific Coast (won by Sam Hanks) and Short Track (Troy Ruttman).

TORC: The Off-Road Championship was founded in 2009 by motocross racer Rick Johnson and it was managed the race operations and officiated the events.